Axial fan design

An axial fan is a type of fan that makes gas flow through it in an axial direction, from entry to exit and parallel to the shaft about which the blades rotate. The fan is designed to produce a pressure difference, and so a force, that drives the flow. How well it performs depends on the number, angle and shape of the blades. Axial fans generally have fewer blades, typically two to six, than centrifugal fans, and they commonly have a larger radius and a lower speed than ducted fans. Design work centers on the parameters of power, flow rate, pressure rise and efficiency. Axial fans are used in many applications, including wind tunnels and cooling towers.